The present invention generally relates to an electrical connection box which contains electrical connection components such as a blade fuse, a slow blowing fuse, a relay, etc. so as to supply electric current to a portion of a wiring provided in a motor vehicle and more particularly, to a fitting construction of the electrical connection box, which includes a casing member made of resin and a cover member made of resin and mounted on the casing member, the cover member being formed, on a lower surface of its peripheral wall, with a downwardly opening fitting groove, while the casing member is formed, at an upper end of its peripheral wall, with a projection such that the projection is fitted into the fitting groove.
With reference to FIG. 1 showing an electrical connection box of the present invention, a general electrical connection box is briefly described. The electrical connection box includes a casing member 1 made of resin and acting as a lower casing and a cover member 2 for preventing entry of water into the casing member 1, which is made of resin and is mounted on the casing member 1 so as to cover an upper opening of the casing member 1. A fitting portion 5 formed at an upper end of a peripheral wall of the casing member 1 is fitted into a fitting portion 6 formed on a lower surface of the cover member 2 such that the casing member 1 and the cover member 2 are locked to each other through engagement between upper locking portions 7 of the cover member 2 and lower locking portions 8 of the casing member 1, respectively.
FIG. 5 shows a fitting construction of a known electrical connection box. In FIG. 5, a downwardly opening fitting groove 10 is formed at the fitting portion 6 of the cover member 2. In order to impart hermetic property to the cover member 2, a rubber packing 11 is fitted into the fitting groove 10. Meanwhile, a projection 13 of a cross-sectional shape having a thin distal end is formed on the fitting portion 5 of the casing member 1. By pressing an upper end face of the projection 13 against the packing 11 at the time of fitting of the fitting portion 5 of the casing member 1 into the fitting portion 6 of the cover member 2, mounting feeling and waterproof property of the cover member 2 are secured.
In the known electrical connection box of this kind, since the rubber packing 11 is provided, the number of components of the known electrical connection box and assembly steps of the known electrical connection box are increased, thereby resulting in rise of its production cost. On the other hand, if the packing 11 is merely eliminated, hermetic property and waterproof property of the electrical connection box are deteriorated.